1. Field of the Invention
This invention relates to material handling methods and apparatus and in particular to a method of transferring an article from a first moving conveyor to a second moving conveyor and apparatus for effecting the same.
2. Description of the Prior Art
In one conventional form of conveyor such as used in assembly lines in the manufacture of appliances, such as washers and the like, relatively bulky and heavy articles, such as washer cabinets and the like, are conveyed by conveyors along preselected assembly lines. The article may conventionally be suspended from hooks on the conveyors by means of suitable hangers associated with the articles.
In many applications, the articles must be subsequently transferred to a second conveyor for further manufacturing operations on a subsequent assembly line or for delivery of the articles such as for warehousing and the like. It has been conventional to manually remove the articles from the first conveyor and transfer the articles to the second conveyor. Such manual transferring operation is costly, and physically difficult for workers especially when the articles are relatively heavy and unwieldy. Commercially available parts transfer apparatus such as industrial robots are not capable of exercising the human judgement necessary to transfer articles to a conveyor on which it is necessary to add articles selectively.
Even industrial robots which are programable, such as those available from Auto Place, Inc. of Troy, Michigan, are not capable of operating under many conditions existing in modern industrial facilities.
Prior art apparatus such as shown in U.S. Pat. Nos. 2,628,702; 2,771,174; and 3,370,723 do not meet the needs of an application where selective transfer of articles is desirable or required.